CN110744782A

CN110744782A - Rotary pipe making device

Info

Publication number: CN110744782A
Application number: CN201911037785.9A
Authority: CN
Inventors: 高雪芹; 陈斌; 杨浩; 申开智
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2019-10-29
Filing date: 2019-10-29
Publication date: 2020-02-04

Abstract

The invention discloses a rotary pipe making device which comprises an extruder, a motor, an upper die, a lower die, a core rod, a rotary conductive mechanism, a cooling mechanism and an electric box, wherein the upper die and the lower die are fixedly connected, the core rod is arranged between the upper die and the lower die, and a sealed cavity is formed among the upper die, the lower die, the core rod and a deep groove ball bearing; an output shaft of the motor is fixedly connected with the core rod, the rotary conductive mechanism is arranged between the core rod and the motor, and a core rod cooling channel, a core rod thermocouple and a core rod heating rod are arranged in the core rod; an upper die cooling channel and an upper die sprue are arranged on the upper die, a lower die cooling channel and a lower die sprue are arranged on the lower die, and the melt is extruded to the cavity by the extruder; the cooling mechanism is respectively connected with the core rod cooling channel, the upper die cooling channel and the lower die cooling channel. The invention improves the condition that the molecular chain of the pipe processed by the traditional extrusion is oriented along the axial direction and the molecular chain isotropy and a large number of welding lines of the pipe formed by the traditional injection molding, and improves the circumferential mechanical property of the pipe.

Description

Rotary pipe making device

Technical Field

The invention belongs to polymer forming and processing equipment, and particularly relates to a novel rotary pipe making device capable of independently regulating and controlling temperature, pressure and annular direction.

Background

The final properties and structure of polymeric materials are more dependent on the molding process than typical materials. Under the synergistic action of the processing stress field and the temperature field, polymer macromolecules can move, relax and reorganize to form different aggregation state structures. This also theoretically offers the possibility of morphological control. Generally, the molecular chain is randomly oriented, so that the actual mechanical property of the polymer material is far lower than the theoretical value, and the properties of the polymer material can be greatly improved by controlling the condensed structure of the polymer, for example, the properties such as tensile strength, modulus, fracture toughness and the like can be greatly improved by improving the molecular chain orientation.

The orientation of the polymer molecular chain is realized by the cooperative motion of the whole chain and the chain segment, and the viscous resistance in the polymer is overcome under the action of external force, so that the molecular chain is orderly arranged, and the mechanical property along the orientation direction is obviously improved. The polymer pipeline has the advantages of low density, corrosion resistance, energy conservation, convenience in transportation, high stability and the like, so that the polymer pipeline is widely applied to various industries, particularly urban gas/hot water supply, water supply and drainage, agricultural irrigation and electrical casing pipes.

The pipeline system consists of pipes, pipe fittings and valves. For a traditional extrusion molding plastic pipe, under the stretching action of a traction device, polymer macromolecular chains in the pipe are oriented along the extrusion direction, so that the axial performance of the pipe is higher than the circumferential performance of the pipe; and the structure of the traditional polyolefin injection molding pipe fitting is isotropic under a static field, and a large number of welding lines with weak strength are generated. However, in the conventional process pipes and tubes which actually bear internal pressure, the circumferential stress is twice as much as the axial stress. Therefore, when the pressure in the pipe exceeds a certain critical value, the plastic pipe generates yield failure and is broken along the axial direction, and the service life of the pipe is reduced. In order to improve the circumferential performance of the pipe, the traditional rotary extrusion method adopted in the past enables the polymer melt extruded by the screw to be subjected to the comprehensive action of a rotary shearing force field and a stretching force field, but the molecular chain orientation condition under the state of a single force field cannot be explored, and a weld mark is easily formed by a shunt shuttle, so that the circumferential mechanical performance is improved to a limited extent, the wall thickness of the pipe still needs to be increased, the intermolecular acting force is improved, the raw material and the energy are wasted, and the difficulty in cooling and shaping in the process is improved. Based on the defects of the prior art, a new technology capable of effectively improving the annular pressure bearing of the plastic pipe fitting needs to be researched and developed.

Disclosure of Invention

The invention aims to provide a rotary pipe making device, which improves the conditions of the molecular chain orientation of a pipe processed by traditional extrusion along the axial direction and the molecular chain isotropy and a large number of welding lines of a pipe fitting formed by traditional injection molding, improves the circumferential mechanical property of the pipe fitting, further reduces the wall thickness of the pipe fitting, and achieves a green manufacturing mode of reducing the cost.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a rotary pipe making device comprises an extruder, a motor, an upper die, a lower die, a core rod, a rotary conductive mechanism, a cooling mechanism and an electric box, wherein the upper die and the lower die are fixedly connected, the core rod is installed between the upper die and the lower die through a deep groove ball bearing, and a sealed cavity is formed among the upper die, the lower die, the core rod and the deep groove ball bearing; the output shaft of the motor is fixedly connected with the core rod, the rotary conductive mechanism is arranged between the core rod and the motor, a core rod cooling channel, a core rod thermocouple and a core rod heating rod are arranged in the core rod, and the core rod thermocouple and the core rod heating rod are connected with the electric box through the rotary conductive mechanism; the upper die is provided with an upper die cooling channel and an upper die sprue communicated with the cavity, the lower die is provided with a lower die cooling channel and a lower die sprue communicated with the cavity, and the extruder extrudes the melt to the cavity through the upper die sprue and the lower die sprue; and the cooling mechanism is respectively connected with the core rod cooling channel, the upper die cooling channel and the lower die cooling channel to form a cooling loop.

The rotary conductive mechanism comprises a conductive copper ring, a carbon brush and a support, the conductive copper ring is fixed between the motor and the mandrel, the carbon brush is arranged on one side of the conductive copper ring through the support and is in contact with the conductive copper ring, the carbon brush is connected with the electric box through a wire, and the conductive copper ring is respectively connected with the mandrel thermocouple and the mandrel heating rod through wires.

The number of the conductive copper rings and the number of the carbon brushes are 4, the core rod thermocouple is connected with the electric box through two of the conductive copper rings and two of the carbon brushes, and the core rod heating rod is connected with the electric box through the other two conductive copper rings and the other two carbon brushes.

The output shaft of the motor is fixedly connected with the mandrel through a rotating shaft A, a coupling A, a rotating shaft B and the coupling A which are fixedly connected in sequence, and the conductive copper ring is fixed on the rotating shaft B.

The upper die is internally provided with an upper die heating rod and an upper die thermocouple, the lower die is internally provided with a lower die heating rod, a lower die thermocouple and a pressure sensor, and the upper die heating rod, the upper die thermocouple, the lower die heating rod, the lower die thermocouple and the pressure sensor are all connected with the electric box.

The mould heating rod is arranged along the width direction symmetry of the upper mould, the lower mould heating rod is arranged along the width direction symmetry of the lower mould, and the upper mould thermocouple and the lower mould thermocouple are both located in the middle of the mould cavity.

The electric box is provided with a machine head temperature display, a melt pressure display, a core rod temperature display, an upper die temperature display and a lower die temperature display, the machine head temperature display is connected with a sensor used for measuring the temperature of the machine head of the extruder, the melt pressure display is connected with the pressure sensor, the core rod temperature display is connected with a core rod thermocouple, the upper die temperature display is connected with an upper die thermocouple, and the lower die temperature display is connected with a lower die thermocouple.

The cooling mechanism comprises an oil cylinder and a cooling pipe, the oil cylinder comprises an oil outlet end and an oil return end, the oil outlet end of the oil cylinder is connected with the liquid inlet end of the core rod cooling channel, the liquid inlet end of the upper die cooling channel and the liquid inlet end of the lower die cooling channel respectively, and the oil return end of the oil cylinder is connected with the liquid outlet end of the core rod cooling channel, the liquid outlet end of the upper die cooling channel and the liquid outlet end of the lower die cooling channel respectively.

The upper die is provided with a boss and a plurality of upper screw holes, and the boss is respectively positioned at four corners of the upper die; the lower die is provided with a concave platform corresponding to the boss and a lower screw hole corresponding to the upper screw hole, and the upper die and the lower die are positioned through the boss and the concave platform and fixed through screws rotating into the upper screw hole and the lower screw hole.

Bearing key grooves are formed in two ends of the core rod, and the deep groove ball bearings are assembled on the core rod through the bearing key grooves.

The invention has the advantages that:

1. according to the invention, the motor drives the core rod arranged between the upper die and the lower die to rotate, and the annular shearing can be carried out on the viscous-state molecular chain injected into the cavity, so that the orientation of the molecular chain segment along the axial direction is greatly reduced, the orientation degree in the circumferential direction is improved, and the annular performance of the plastic pipe is greatly improved. The structure that makes plug thermocouple and plug heating rod be connected with the electronic box through rotatory conductive mechanism can realize the rotation type heating of plug, is favorable to improving tubulation efficiency. And the cooling mechanism is respectively connected with the core rod cooling channel, the upper die cooling channel and the lower die cooling channel to form a cooling loop, so that the prepared pipe can be cooled from the inside and the outside of the pipe at the same time, and the forming of the pipe is accelerated. In addition, the annular shearing of the die can be realized at different shearing rates and shearing time. Therefore, the invention can expand the field of practical application and provide theoretical guiding research for the actual production of factories.

2. The invention adopts a mode of combining the conductive copper ring and the carbon brush to form the rotary conductive mechanism, and realizes the rotary or non-rotary heating of the melt (polymer melt) from the center of the cavity through the core rod.

3. The number of the conductive copper rings and the number of the carbon brushes are set to be 4, the mandril thermocouple is connected with the electric box through two of the conductive copper rings and two of the carbon brushes, and the mandril heating rod is connected with the electric box through the other two conductive copper rings and the other two carbon brushes. Such a structure is advantageous for ensuring stable transmission of electric power and preventing the winding of the wire during the rotation of the mandrel.

4. The motor is fixedly connected with the core rod through the rotating shaft A, the coupling A, the rotating shaft B and the coupling A which are fixedly connected in sequence, and the conductive copper ring is fixed on the rotating shaft B. The structure can enable the core rod to have a heating function on the basis that the motor stably drives the core rod to rotate.

5. The invention is provided with an upper die heating rod and an upper die thermocouple in an upper die, and is provided with a lower die heating rod, a lower die thermocouple and a pressure sensor in a lower die. The pressure sensor can detect whether the melt (polymer melt) in the cavity is filled in the whole die cavity and measure the pressure in the cavity, so that the product performance under the molding conditions of different pressures is explored. Through the cooperation of the upper die heating rod, the upper die thermocouple, the lower die heating rod and the lower die thermocouple, a melt (polymer melt) can be heated from the surface of a cavity of the die. And the annular heating device is matched with the core rod with the heating function, and can also control the device to perform annular shearing at different temperature states, so that non-isothermal heating and isothermal heating process conditions are realized, an optimal process window for rotationally preparing the pipe fitting is sought, and a model is established for theoretical research on the circumferential lingering flow condition of annular space melt.

6. According to the invention, the upper die heating rods are symmetrically arranged along the width direction of the upper die, the lower die heating rods are symmetrically arranged along the width direction of the lower die, and the upper die thermocouple and the lower die thermocouple are both arranged in the middle of the cavity, so that the structure ensures the heating stability and the temperature measurement accuracy, and is beneficial to improving the product quality.

7. The electric box is provided with the machine head temperature display, the melt pressure display, the core rod temperature display, the upper die temperature display and the lower die temperature display, and the machine head temperature display, the melt pressure display, the core rod temperature display, the upper die temperature display and the lower die temperature display can respectively and visually display the machine head temperature, the melt pressure in the cavity, the core rod temperature, the upper die temperature and the lower die temperature in real time, so that a basis is provided for preparing high-quality pipes.

8. The cooling mechanism comprises the oil cylinder and the cooling pipe, and the oil cylinder and the cooling pipe are matched with the core rod, the upper die and the lower die to respectively form a cooling loop, so that the pipe can be cooled from the inside and the outside at the same time during forming, the forming of the pipe is accelerated, and the purpose of shortening the pipe manufacturing time is achieved.

9. The upper die is provided with the boss and the plurality of upper screw holes, the lower die is provided with the concave platform and the lower screw holes, and the boss and the concave platform are convenient for the accurate positioning of the upper die and the lower die during die assembly; through the cooperation of a plurality of upper screw holes and a plurality of lower screw holes, can make the die joint in close contact with of mould and lower mould to prevent that the eccentric moment that rotatory shearing field brought from producing the flash.

10. According to the invention, the bearing key grooves are formed in the two ends of the core rod, and the deep groove ball bearings are assembled on the core rod through the bearing key grooves, so that the core rod can flexibly and freely rotate in the upper die and the lower die.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the structure of the mandrel of the present invention;

FIG. 3 is a cross-sectional view A-A of the mandrel of FIG. 2;

FIG. 4 is a schematic view of the structure of the lower mold in the present invention;

FIG. 5 is a cross-sectional view A-A of FIG. 4;

FIG. 6 is a cross-sectional view B-B of FIG. 4;

FIG. 7 is a schematic view of the upper die of the present invention;

FIG. 8 is a cross-sectional view A-A of FIG. 7;

FIG. 9 is a cross-sectional view B-B of FIG. 7;

FIG. 10 is a graph of the verification results of the present invention;

labeled as: 1. an oil cylinder, 2, an extruder, 3, a lower die, 4, a coupler B, 5, a conductive copper ring, 6, a rotating shaft B, 7, a coupler A, 8, a rotating shaft A, 9, a motor, 10, a machine head temperature display, 11, a melt pressure display, 12, an electric box, 13, a mandrel temperature display, 14, an upper die temperature display, 15, a lower die temperature display, 16, a bracket, 17, a carbon brush, 18, an upper die, 19, a deep groove ball bearing A, 20, a mandrel, 21, a deep groove ball bearing B, 22, a cooling pipe, 23, a screw fixing hole, 24, a mandrel heating rod, 25, a mandrel cooling channel, 26, a bearing key groove, 27, a mandrel thermocouple, 28, a lower screw hole, 29, a concave table, 30, a lower die sprue, 31, a pressure sensor, 32, a lower die thermocouple, 33, a lower die inner cavity, 34, a lower die heating rod, 35, a lower die cooling channel, 36 and an upper screw hole, 37. an upper die sprue 38, an upper die cooling channel 39, an upper die heating rod 40, a boss 41, an upper die inner cavity 42 and an upper die thermocouple.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

The invention discloses a rotary pipe making device, which comprises an extruder 2, a motor 9, an upper die 18, a lower die 3, a core rod 20, a rotary conductive mechanism, a cooling mechanism and an electric box 12, wherein the upper die 18 comprises an upper die inner cavity 41, the lower die 3 comprises a lower die inner cavity 33, the upper die 18 is fixedly connected with the lower die 3, and a cavity is formed between the upper die 18 and the lower die 3 after the fixing; the core rod 20 is installed between the upper die 18 and the lower die 3 through deep groove ball bearings, the number of the deep groove ball bearings is two, the deep groove ball bearings are respectively a19 and a B21, the A19 and the B21 are both fixed between the upper die 18 and the lower die 3, the A19 and the B21 are respectively located at two ends of the core rod 20, after the core rod 20 is installed between the upper die 18 and the lower die 3 through the two deep groove ball bearings, a sealed cavity is formed among the upper die 18, the lower die 3, the core rod 20 and the deep groove ball bearings, and the cavity is used for forming a pipe. An output shaft of the motor 9 is fixedly connected with the core rod 20, the motor 9 adopts a three-phase asynchronous motor 9 and is used for driving the core rod 20 to rotate, and the rotary conductive mechanism is arranged between the core rod 20 and the motor 9. As shown in fig. 2-3, a mandrel cooling channel 25, a mandrel thermocouple 27 and a mandrel heating rod 24 are disposed in the mandrel 20, and both the mandrel thermocouple 27 and the mandrel heating rod 24 are connected to the electrical box 12 through a rotary conductive mechanism. Specifically, the opening of the mandrel cooling channel 25 is located at one end of the mandrel 20, two blind holes are formed in the mandrel 20, the openings of the two blind holes are located at two ends of the other end of the mandrel 20, the mandrel thermocouple 27 and the mandrel heating rod 24 are fixed in the blind holes, and the temperature of the polymer melt in the cavity can be effectively controlled through the cooperation of the mandrel thermocouple 27 and the mandrel heating rod 24. As shown in fig. 4-9, the upper mold 18 is provided with an upper mold cooling channel 38 and an upper mold gate 37 communicating with the cavity, the lower mold 3 is provided with a lower mold cooling channel 35 and a lower mold gate 30 communicating with the cavity, both the upper mold gate 37 and the lower mold gate 30 are located at one end of the cavity, and the upper mold gate 37 corresponds to the lower mold gate 30; after the upper die 18 and the lower die 3 are fixed, the upper die sprue 37 and the lower die sprue 30 form a complete pouring hole, the head of the extruder 2 is fixed in the pouring hole, the central line of the head of the extruder 2 and the parting surface of the die are in the same plane, and the extruder 2 extrudes melt to a cavity through the pouring hole formed by combining the upper die sprue 37 and the lower die sprue 30. The cooling mechanism is respectively connected with the core rod cooling channel 25, the upper mold cooling channel 38 and the lower mold cooling channel 35 and respectively forms independent cooling loops.

In the invention, as shown in fig. 1, the rotating conductive mechanism comprises a conductive copper ring 5, a carbon brush 17 and a support 16, the conductive copper ring 5 is fixed between a motor 9 and a mandrel 20, the carbon brush 17 is arranged on one side of the conductive copper ring 5 through the support 16 and is contacted with the conductive copper ring 5, the carbon brush 17 is connected with an electric box 12 through a wire, and the conductive copper ring 5 is respectively connected with a mandrel thermocouple 27 and a mandrel heating rod 24 through wires. The number of the conductive copper rings 5 and the number of the carbon brushes 17 are preferably 4, the conductive copper rings 5 correspond to the carbon brushes 17 one by one, the positive electrode and the negative electrode of the mandrel thermocouple 27 are respectively connected with the electric box 12 through two of the conductive copper rings 5 and two of the carbon brushes 17, and the live wire and the zero wire of the mandrel heating rod 24 are respectively connected with the electric box 12 through the other two conductive copper rings 5 and the other two carbon brushes 17. Thus, the mandrel heating rod 24 can form a conductive path with the electric box 12 through the conducting wire, the conducting copper ring 5 and the carbon brush 17, and the mandrel thermocouple 27 can form a conductive path with the electric box 12 through the conducting wire, the conducting copper ring 5 and the carbon brush 17, so that the heating and the temperature detection of the mandrel 20 in a non-rotating or rotating state are realized.

Further, the output shaft of the motor 9 is fixedly connected with the mandrel 20 through a rotating shaft A8, a coupling a7, a rotating shaft B6 and a coupling a7 which are sequentially and fixedly connected, and the conductive copper ring 5 is fixed on the rotating shaft B6, so that the rotating shaft A8, the coupling a7, the rotating shaft B6 and the coupling a7, the conductive copper ring 5 and the mandrel 20 can realize the rotation movement with the unchanged synchronous central line, and a certain rotation shearing field is given to the polymer melt at the moment to form a circumferential dragging stress field. Further, by controlling the rotating speed of the motor 9, the morphology distribution of the polymer under different shear force fields can be explored.

In the invention, as shown in fig. 4-9, an upper mold heating rod 39 and an upper mold thermocouple 42 are arranged in the upper mold 18, a lower mold heating rod 34, a lower mold thermocouple 32 and a pressure sensor 31 are arranged in the lower mold 3, the upper mold heating rod 39 is symmetrically arranged along the width direction of the upper mold 18, the lower mold heating rod 34 is symmetrically arranged along the width direction of the lower mold 3, the upper mold thermocouple 42 and the lower mold thermocouple 32 are both positioned in the middle of the cavity, and the upper mold heating rod 39, the upper mold thermocouple 42, the lower mold heating rod 34, the lower mold thermocouple 32 and the pressure sensor 31 are all connected with the electric box 12. Wherein, the other end of the lower die 3 corresponding to the upper die gate 37/the lower die gate 30 is provided with a blind hole, the pressure sensor 31 is arranged in the blind hole and is connected with the electric box 12 through a lead, whether the whole die cavity is filled with polymer melt or not can be judged, the pressure in the die cavity can be measured, and the product performance under the molding conditions of different pressures can be researched.

In the invention, as shown in fig. 1, a head temperature display 10, a melt pressure display 11, a mandrel temperature display 13, an upper die temperature display 14 and a lower die temperature display 15 are arranged on an electric box 12, and the head temperature display 10 is connected with a sensor for measuring the head temperature of an extruder 2 and is used for displaying the temperature set by the head of the extruder 2; the melt pressure display 11 and the pressure sensor 31 are used for displaying the melt pressure in the cavity so as to judge whether the polymer melt is filled in the whole mold cavity and measure the pressure in the cavity; the core rod temperature display 13 is connected with the core rod thermocouple 27 and used for displaying the temperature of the core rod 20, and the upper die temperature display 14 is connected with the upper die thermocouple 42 and used for displaying the temperature of the upper die 18; the lower die temperature display 15 is connected with the lower die thermocouple 32 and is used for displaying the temperature of the lower die 3; so that the core rod heating rod 24, the upper mold heating rod 39 and the lower mold heating rod 34 can adjust the temperature of the polymer melt in the cavity according to the respective displayed temperatures in order to achieve the optimal tube-making temperature.

In the invention, the cooling mechanism comprises an oil cylinder 1 and a cooling pipe 22, the oil cylinder 1 comprises an oil outlet end and an oil return end, the oil outlet end of the oil cylinder 1 is respectively connected with the liquid inlet end of the core rod cooling channel 25, the liquid inlet end of the upper mold cooling channel 38 and the liquid inlet end of the lower mold cooling channel 35, the oil return end of the oil cylinder 1 is respectively connected with the liquid outlet end of the core rod cooling channel 25, the liquid outlet end of the upper mold cooling channel 38 and the liquid outlet end of the lower mold cooling channel 35, and the oil cylinder 1 can form an independent cooling loop with the core rod cooling channel 25, the upper mold cooling channel 38 and the lower mold cooling channel 35 through the. Specifically, the mandrel cooling channel 25 is provided with a liquid inlet end and a liquid outlet end which are respectively connected with the liquid outlet end and the liquid inlet end of the oil cylinder 1, the upper die cooling channel 38 and the lower die cooling channel 35 are similar in structure, after the oil cylinder 1 forms an independent cooling loop with the mandrel cooling channel 25, the upper die cooling channel 38 and the lower die cooling channel 35 through the cooling pipe 22, the main channel is divided twice and converged three times through the branch channels at different stages, and cooling is performed in the form of main stream-flow dividing-main stream channel.

In the invention, the upper die 18 is provided with a boss 40 and a plurality of upper screw holes 36, the boss 40 is respectively positioned at four corners of the upper die 18, and the plurality of upper screw holes 36 are uniformly arranged on the upper die 18; the lower die 3 is provided with a concave platform 29 corresponding to the boss 40 and a lower screw hole 28 corresponding to the upper screw hole 36, and the upper die 18 and the lower die 3 are positioned through the boss 40 and the concave platform 29 so as to be convenient for accurate die assembly; the upper die 18 and the lower die 3 are fixed by screws screwed into the upper screw hole 36 and the lower screw hole 28, so that parting surfaces of the upper die 18 and the lower die 3 are tightly combined, and flash caused by eccentric moment due to a rotary shearing field is prevented. When the pipe taking-out device is used, the upper die 18 can be opened when the pipe needs to be taken out by turning the screw anticlockwise through a tool such as a wrench and the like.

In the present invention, bearing key grooves 26 are formed at both ends of the mandrel 20, and the deep groove ball bearing a19 and the deep groove ball bearing B21 are fitted to the mandrel 20 through the bearing key grooves 26. Further, a screw fixing hole 23 is formed in the core rod 20, an opening of the screw fixing hole 23 and an opening of a blind hole for installing the core rod thermocouple 27 are located at the same end, and a screw is installed in the screw fixing hole 23 and used for locking the deep groove ball bearing B21 and the core rod 20.

In the present invention, the extruder 2 may be any of various conventional apparatuses. Before use, the temperature of the feeding section, the compression section and the homogenization section of the extruder 2 are respectively set, a head temperature display 10 on an electric box 12 displays the temperature set by the head of the extruder 2, polymer particles are added, and after full melting and plasticizing, a high molecular melt is extruded at a certain screw rotating speed.

The pipe making process of the invention comprises the following steps:

firstly, the temperatures of the extruder 2, the upper die 18, the lower die 3 and the core rod 20 are set and heating is started, then polymer particles are subjected to uniform plasticizing action of the extruder 2, polymer melt is extruded into a cavity between the upper die 18 and the lower die 3 through a pouring hole, the pressure sensor 31 judges that the melt is full of the cavity, then the core rod heating rod 24, the upper die heating rod 39 and the lower die heating rod 34 are closed, and heating is stopped. And starting the motor 9, setting the rotating speed of the motor 9, and rotating the core rod 20 under the action of the frequency converter, the rotating shaft A8, the coupling A7, the rotating shaft B6 and the coupling A7 to form a certain annular stress field for the polymer molecular chain segment. Meanwhile, the oil cylinder 1 is opened to cool the upper die 18, the lower die 3 and the core rod 20, and the inner and outer tube walls of the product are cooled in a circulating cooling mode in the cooling process, so that the product is gradually cooled towards the core layer. And (3) when the melt is completely cooled, closing the oil cylinder 1 and the motor 9, unscrewing a screw on the die by a wrench, opening the die, and taking out the pipe to form a mouth. Because the molecular chain segment of the polymer melt is subjected to the action of pure circumferential shear force in the process of preparing the pipe, the degree of the product oriented along the circumferential direction is greatly improved, and the quality of the product is further improved.

The pipe articles prepared according to the invention were verified as follows:

the verification method comprises the following steps: the effect of the experiment was investigated by determining the orientation of the molecular chain segments by observation with a Scanning Electron Microscope (SEM).

Verifying parameters: under qualitative observation of SEM, the number of random coil-like spherulites and highly oriented clusters is proportional.

And (4) verification result: as shown in FIG. 10, in the plastic processing process, under the application of a rotating shear field, the crystals are oriented along the circumferential direction of the pipe, and the number of formed series crystals is far higher than that of spherulites.

The verification results prove that the annular mechanical property of the pipe fitting can be improved, the wall thickness of the pipe fitting is reduced, and the green manufacturing mode for reducing the cost is achieved.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rotary pipe making device is characterized in that: the device comprises an extruder (2), a motor (9), an upper die (18), a lower die (3), a core rod (20), a rotary conductive mechanism, a cooling mechanism and an electric box (12), wherein the upper die (18) is fixedly connected with the lower die (3), the core rod (20) is installed between the upper die (18) and the lower die (3) through a deep groove ball bearing, and a sealed cavity is formed among the upper die (18), the lower die (3), the core rod (20) and the deep groove ball bearing; the output shaft of the motor (9) is fixedly connected with the core rod (20), the rotary conductive mechanism is arranged between the core rod (20) and the motor (9), a core rod cooling channel (25), a core rod thermocouple (27) and a core rod heating rod (24) are arranged in the core rod (20), and the core rod thermocouple (27) and the core rod heating rod (24) are connected with the electric box (12) through the rotary conductive mechanism; an upper die cooling channel (38) and an upper die sprue (37) communicated with the cavity are formed in the upper die (18), a lower die cooling channel (35) and a lower die sprue (30) communicated with the cavity are formed in the lower die (3), and the melt is extruded to the cavity by the extruder (2) through the upper die sprue (37) and the lower die sprue (30); and the cooling mechanism is respectively connected with the core rod cooling channel (25), the upper die cooling channel (38) and the lower die cooling channel (35) to form a cooling loop.

2. The novel rotary pipe making device according to claim 1, wherein: rotatory electrically conductive mechanism includes electrically conductive copper ring (5), carbon brush (17) and support (16), and electrically conductive copper ring (5) are fixed between motor (9) and plug (20), and carbon brush (17) set up in electrically conductive copper ring (5) one side and contact with electrically conductive copper ring (5) through support (16), and carbon brush (17) are connected with electronic box (12) through the wire, and electrically conductive copper ring (5) are connected with plug thermocouple (27) and plug heating rod (24) respectively through the wire.

3. A novel rotary pipe making device according to claim 2, wherein: the number of the conductive copper rings (5) and the number of the carbon brushes (17) are 4, the mandril thermocouple (27) is connected with the electric box (12) through two of the conductive copper rings (5) and two of the carbon brushes (17), and the mandril heating rod (24) is connected with the electric box (12) through the other two conductive copper rings (5) and the other two carbon brushes (17).

4. A novel rotary pipe making apparatus according to any one of claims 1 to 3, wherein: the output shaft of the motor (9) is fixedly connected with the core rod (20) through a rotating shaft A (8), a shaft coupling A (7), a rotating shaft B (6) and the shaft coupling A (7) which are fixedly connected in sequence, and the conductive copper ring (5) is fixed on the rotating shaft B (6).

5. A novel rotary pipe making apparatus according to any one of claims 1 to 3, wherein: the improved electric box is characterized in that an upper die heating rod (39) and an upper die thermocouple (42) are arranged in the upper die (18), a lower die heating rod (34), a lower die thermocouple (32) and a pressure sensor (31) are arranged in the lower die (3), and the upper die heating rod (39), the upper die thermocouple (42), the lower die heating rod (34), the lower die thermocouple (32) and the pressure sensor (31) are all connected with the electric box (12).

6. The novel rotary pipe making device according to claim 5, wherein: go up mould heating rod (39) and set up along the width direction symmetry of last mould (18), lower mould heating rod (34) sets up along the width direction symmetry of lower mould (3), it all is located the die cavity middle part to go up mould thermocouple (42) and lower mould thermocouple (32).

7. The novel rotary pipe making device according to claim 5, wherein: be provided with aircraft nose temperature display (10) on electronic box (12), fuse-element pressure display (11), plug temperature display (13), go up mould temperature display (14) and lower mould temperature display (15), aircraft nose temperature display (10) are connected with the sensor that is used for measuring extruder (2) aircraft nose temperature, fuse-element pressure display (11) and pressure sensor (31), plug temperature display (13) are connected with plug thermocouple (27), it is connected with last mould thermocouple (42) to go up mould temperature display (14), lower mould temperature display (15) are connected with lower mould thermocouple (32).

8. The novel rotary pipe making device according to claim 1, wherein: the cooling mechanism comprises an oil cylinder (1) and a cooling pipe (22), the oil cylinder (1) comprises an oil outlet end and an oil return end, the oil outlet end of the oil cylinder (1) is connected with the liquid inlet end of the core rod cooling channel (25), the liquid inlet end of the upper die cooling channel (38) and the liquid inlet end of the lower die cooling channel (35) respectively, and the oil return end of the oil cylinder (1) is connected with the liquid outlet end of the core rod cooling channel (25), the liquid outlet end of the upper die cooling channel (38) and the liquid outlet end of the lower die cooling channel (35) respectively.

9. The novel rotary pipe making device according to claim 1, wherein: the upper die (18) is provided with a boss (40) and a plurality of upper screw holes (36), and the boss (40) is respectively positioned at four corners of the upper die (18); the lower die (3) is provided with a concave platform (29) corresponding to the boss (40) and a lower screw hole (28) corresponding to the upper screw hole (36), and the upper die (18) and the lower die (3) are positioned through the boss (40) and the concave platform (29) and are fixed through screws which are screwed into the upper screw hole (36) and the lower screw hole (28).

10. The novel rotary pipe making device according to claim 1, wherein: bearing key grooves (26) are formed in two ends of the core rod (20), and the deep groove ball bearings are assembled on the core rod (20) through the bearing key grooves (26).